Image sensing apparatus, registration apparatus, and control method and program therefor

ABSTRACT

A lens unit  1  acquires identification information for an attached lens unit from the lens unit and stores the acquired identification information in a second memory  37 . In a case in which correction information for the stored identification information is not registered, a CPU  36  reads the correction information for the stored identification information out from an external memory  39  and registers it.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image sensing apparatus, aregistration apparatus, and a control method and program therefore.

2. Description of the Related Art

The quality of a sensed image of an image sensing apparatus largelydepends on the optical characteristics of the lens unit attached at thetime of image sensing. The optical characteristics of the lens unit thataffects the quality of the sensed image include, for example,magnification chromatic aberration, distortion aberration, and decreasedmarginal illumination. Conventionally, in image sensing apparatusescapable of image processing of sensed images, such as digital stillcameras and the like, there are some that carry out correction accordingto the optical characteristics of the lens unit described above.Japanese Patent Laid-Open No. 2002-199410 discloses photoelectricallyconverting incident light striking an image sensor into analog signalsand further into digital signals using A/D conversion, after whichoptical system image degradation is corrected.

Since lens unit optical characteristics are different for every model,it is necessary to register correction information for the model of lensunit to be attached in the image sensing apparatus. As a technology thatregisters such correction information in the image sensing apparatus,that which is described in Japanese Patent Laid-Open No. 2006-267770 isknown. Japanese Patent Laid-Open No. 2006-267770 discloses an imagesensing apparatus that receives from the lens unit that is attached tothe apparatus main unit information unique to that lens unit, andthrough a computer network acquires correction information correspondingto that unique information.

In the above-described conventional art, during the time in which theimage sensing apparatus is connected to the computer network and iscapable of registering correction information, only correctioninformation relating to the lens unit that is attached to the apparatusmain unit is registered. Therefore, when registering correctioninformation for a plurality of lens units, it is necessary to change thelens unit that is attached to the image sensing apparatus during thattime when the apparatus can register correction information, thuscomplicating registration.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the abovesituation, and provides an image sensing apparatus, a registrationapparatus, and a control method and program therefore capable ofcarrying out registration of lens unit correction information with ease.

According to the present invention, provided is an image sensingapparatus including a correction unit that corrects a sensed image basedon correction information for an attached lens unit registered inadvance in a correction information storage unit, in which the lens unitis detachable, the image sensing apparatus comprising: an acquisitionunit that acquires identification information for an attached lens unitfrom the attached lens unit; a storage unit that stores theidentification information acquired by the acquisition unit; aconnection unit that connects to an external device storing multiplepieces of correction information for different lens units byidentification information; and a control unit that reads out correctioninformation for the identification information stored in the storageunit from the external device and registers the read-out correctioninformation in the correction information storage unit when the externaldevice is connected to the image sensing apparatus by the connectionunit.

According to another aspect of the present invention, provided is acontrol method for an image sensing apparatus including a correctionunit that corrects a sensed image based on correction information for anattached lens unit registered in advance in a correction informationstorage unit, in which the lens unit is detachable, and a connectionunit that connects to an external device storing multiple pieces ofcorrection information for different lens units by identificationinformation, the control method comprising: an acquisition step ofacquiring identification information for an attached lens unit from theattached lens unit; a storage step of storing the identificationinformation acquired in the acquisition step; and a control step ofreading out correction information for the identification informationstored in the storage step from the external device and registering theread-out correction information in the correction information storageunit when the external device is connected to the image sensingapparatus by the connection unit.

According to still another aspect of the present invention, provided isa registration apparatus that transmits by telecommunication correctioninformation to be registered in a correction information storage unit toan image sensing apparatus, the image sensing apparatus including thecorrection information storage unit in which correction information fora lens unit/units is registered and an identification informationstorage unit that stores identification information for the attachedlens unit, in which the lens unit is detachable, the registrationapparatus comprising: a storage unit that stores multiple pieces ofcorrection information of different lens units by identificationinformation; and a control unit that communicates with the image sensingapparatus, reads out correction information for the identificationinformation stored in the identification information storage unit fromthe storage unit, and transmits the read-out correction information tothe image sensing apparatus as correction information to be registeredwhen the registration apparatus is connected to the image sensingapparatus by telecommunication.

Further, according to another aspect of the present invention, providedis a control method for a registration apparatus that includes a storageunit that stores multiple pieces of correction information of differentlens units by identification information, the correction informationstorage unit in which correction information for a lens unit/units isregistered and an identification information storage unit that storesidentification information for an attached lens unit, and that transmitsby telecommunication correction information to be registered in acorrection information storage unit to an image sensing apparatus inwhich the lens unit is detachable, the registration apparatus controlmethod comprising a control step of communicating with the image sensingapparatus, reading out lens unit correction information for theidentification information stored in the identification informationstorage unit from the storage unit, and transmitting the read-outcorrection information to the image sensing apparatus as correctioninformation to be registered when the registration apparatus isconnected to the image sensing apparatus by telecommunication.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments (with reference to theattached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a lens unit and an image sensingapparatus according to a first embodiment;

FIG. 2 is a block diagram of an internal configuration of the imagesensing apparatus according to the first embodiment;

FIGS. 3A and 3B are schematic diagrams illustrating examples of imageprocessing by the image sensing apparatus according to the firstembodiment;

FIG. 4 is a flowchart illustrating processing by the image sensingapparatus according to the first embodiment;

FIG. 5 is a flowchart illustrating processing by the image sensingapparatus according to the first embodiment;

FIG. 6 is a diagram illustrating an example of a user interfaceaccording to the first embodiment;

FIG. 7 is a schematic diagram illustrating a system configurationaccording to a second embodiment; and

FIG. 8 is a flowchart illustrating processing by a registrationapparatus according to a second embodiment.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present invention are described below with referenceto the accompanying drawings. The invention is not limited to thefollowing embodiments, however. Moreover, the embodiments of the presentinvention are exemplary embodiments of the invention and do not limitthe scope of the invention.

(First Embodiment)

A description is now given of a first embodiment. FIG. 1 is a schematicdiagram of an image sensing apparatus 2 according to the presentembodiment. As shown in FIG. 1, the image sensing apparatus 2 is aninterchangeable lens-type digital still camera with a detachable lensunit 1.

The lens unit 1 typically has a zoom lens 11 for changing focal length,an aperture mechanism 12 for controlling brightness, and a focus lens 13for focusing on the subject. In addition, the lens unit 1 has a mountportion 14 for connecting mechanically to a mount portion 27 of theimage sensing apparatus 2, so that the lens unit 1 can be detachablyattached to the image sensing apparatus 2 by screwing the lens unit 1into the image sensing apparatus 2, for example.

The image sensing apparatus 2 reflects light that has passed through thelens unit 1 with a half mirror 21 and forms an image on a focusingscreen 24. The light formed on the focusing screen 24 is inverted by aprism 25, passes through an eyepiece lens 26, and is viewed as an erectimage by a user. During photography, the half mirror 21 pops up, ashutter 22 opens, and light that has passed through the lens unit 1forms an image on an image sensor 23.

The mount portion 14 of the lens unit 1 incorporates contacts 15. Thesecontacts 15 include terminals for receiving a supply of power from theimage sensing apparatus 2 and terminals for exchanging data with theimage sensing apparatus 2 (none of which is shown). More specifically,the contacts 15 are respectively assigned to several applications, suchas power supply, ground, transmission, reception, clock, and the like.By connecting the lens unit 1 mount portion 14 to the image sensingapparatus 2 mount portion 27, connection terminals in the contacts 15 onthe mount portion 14 and in the contacts 28 on the mount portion 27 areconnected to each other. As a result, power is supplied to the lens unit1 and data exchange between the lens unit 1 and the image sensingapparatus 2 is begun.

The lens unit 1 has a drive unit (not shown) such as a stepping motor orthe like for driving the aperture mechanism 12 and the focus lens 13.Through exchanging data with the image sensing apparatus 2, driving ofthe aperture mechanism 12 and the focus lens 13 are controlled from theimage sensing apparatus 2. In addition, the lens unit 1 has a ROM (notshown) storing identification information such as an identificationnumber or lens ID that is uniquely assigned by individual lens unit ormodel for identifying the name, individual lens unit, and model of thelens unit 1. In the event that there has been a request for theabove-described identification information though data exchange with theimage sensing apparatus 2, the lens unit 1 sends the identificationinformation stored in the ROM to the image sensing apparatus 2.

Next, a description is given of the internal configuration of the imagesensing apparatus 2 with reference to FIG. 2.

The image sensor 23 is a CCD or CMOS image sensor or the like. The lightformed on the image sensor 23 is converted into electrical charges ateach of the pixels of the image sensor 23 in accordance with thequantity of incident light. Signals generated by a timing generator (TG)32 drive the image sensor 23, forwarding the electrical chargesaccumulated in the pixels of the image sensor 23 and sequentiallyconverting them into voltage signals. The converted voltage signals arethen sampled and gain-adjusted at a CDS/AGC (Correlated DoubleSampling/Automatic Gain Control) 30 and converted into digital signalsby an A/D converter 31.

The image data converted into digital signals by the A/D converter 31 isinput to an integrated circuit (IC) 33. The image data input to the IC33, after input to a WB unit 33 a that computes data for white balance,is temporarily stored in a first memory 35. The first memory 35 may be aRAM or the like.

The image data temporarily stored in the first memory 35 is once againinput to the IC 33 and the following three types of image processing arecarried out. First, the image data that is once again input to the IC 33is converted into lossless-compressed RAW data at a lossless compressionunit 33 d that subjects the image data as is to lossless compression andsent to a bus 34. In addition, at a thumbnail unit 33 c, for example asshown in FIG. 3A, the image data is passed through a low-pass filter andits bandwidth reduced. It is to be noted that, at the thumbnail unit 33c, as shown in FIG. 3B the image data may be averaged for each block andits bandwidth reduced. Then, the bandwidth-reduced image data issubjected to down-sampling by thinning, converted into a thumbnail imagesmaller in size than the original image, and sent to the bus 34.Finally, in order to produce JPEG (Joint Photographic Experts Group)compressed image data, predetermined image processing is carried out atan image processing unit 33 b on the image data and the processed imagedata is converted into YCbCr data. The YCbCr data is raster-blockconverted, JPEG compressed at the JPEG compression unit 33 e, and sentto the bus 34.

A CPU (Central Processing Unit) 36 centrally controls the operations ofeach part of the image sensing apparatus 2. More specifically,immediately after power to the image sensing apparatus 2 is switched on,the CPU 36 initializes all parts of the image sensing apparatus 2 inaccordance with program data stored in the second memory 37 andcommences communication with the lens unit 1. In addition, the CPU 36temporarily stores sensed image data, which is image data that is outputto the bus 34 after being subjected to image processing by the IC 33, inthe first memory 35. Then, the CPU 36 reads out correction informationfor the lens unit that is attached during image sensing from amongcorrection information for a plurality of lens units stored in thesecond memory 37 to be described later. Then, the CPU 36 corrects theimage data stored in the first memory 35 based on the read-outcorrection information and ultimately stores it in an external memory 39via an I/F unit 38. The second memory 37 is a semiconductor memory orthe like that readably and writably stores data. In addition to theprogram data that the CPU 36 executes, the second memory 37 alsopre-stores various types of setting data including correctioninformation for a plurality of lens units.

In addition, a switch 40 is connected to the CPU 36, and the CPU 36controls the parts of the image sensing apparatus 2 in response toinstructions from the user that are input through the switch 40. Forexample, the switch 40 may be a release switch for accepting aninstruction to shoot, operating switches for carrying out varioussettings, and so forth. The CPU 36, in response to the pressing of therelease switch, carries out image sensing with the image sensor 23, and,after image processing by the IC 33, stores the sensed image data in theexternal memory 39.

The I/F unit 38 is an interface detachably connected to the externalmemory 39 for writing data to the attached external memory 39 or readingout data stored in the attached external memory 39. The external memory39 is a recording medium such as a semiconductor memory or a HDD (HardDisk Drive). It is to be noted that the I/F unit 38 may be a USB,IEEE1394, LAN port or other such interface communicably connected to anexternal device such as a PC, a data server on a network, or the like.In this case, the I/F unit 38 can write data to the external device andread data from the external device. It is to be noted that USB standsfor Universal Serial Bus, and IEEE stands for Institute of Electricaland Electronic Engineers.

A display unit 41 is a display device such as a liquid crystal display(LCD) provided on a rear face of the image sensing apparatus 2, anddisplays images under the control of the CPU 36. By withdrawing the halfmirror 21 from the light path and displaying image data sequentiallysensed by the image sensing sensor 23, for example, the display unit 41can provide electronic viewfinder (EVF) display. In addition, thedisplay unit 41, under the control of the CPU 36, displays operatingscreens when carrying out various settings using the operating switchesof the switch 40.

Next, a description is given of processing performed by the CPU 36 ofthe image sensing apparatus 2 when the lens unit 1 is attached to theimage sensing apparatus 2, with reference to FIG. 4. When the CPU 36detects attachment of the lens unit 1 by connection of the contacts 28and the contacts 15, the CPU 36 commences exchanging data between thelens unit 1 and the image sensing apparatus 2 (step S1). Then, in stepS2, the CPU 36 receives lens ID and other such identificationinformation from the lens unit 1.

Then, the CPU 36 determines whether or not the received lens ID isalready registered in the second memory 37 of the image sensingapparatus 2 (step S3). In step S3, if the received ID is alreadyregistered, the CPU 36 ends this process without registering the lens IDin the second memory 37 (step S4). On the other hand, if in step S3 thereceived ID is not registered, then the CPU 36 determines whether or notthere is space in the registration area of the second memory 37 to storethe received lens ID (step S5).

In step S5, if there is no space in the registration area, the CPU 36causes the display unit 41 to display a warning message indicting thatthe registration area is full and there is no space to register the lensID of the attached lens unit (step S6). After display of the warningmessage, the CPU 36 ends the process (step S7).

If in step S5 there is space in the registration area, the CPU 36registers history information including the received lens ID in theregistration area of the second memory 37 (step S8). It is to be notedthat, in the present embodiment, in step S8, although the received lensID and lens name are registered as history information in theregistration area of the second memory 37, it is sufficient if the lensID is contained in the history information. Next, the CPU 36 initializessettings related to the newly attached lens unit (step S9) and ends theprocess (step S10).

A brief description is now given of the data that is stored in theregistration area of the second memory 37. The following Table 1 showstable data containing information relating to the lens unit that isstored in the registration area.

TABLE 1 LENS ID LENS NAME DL ON/OFF MAGNIFICATION AXIAL MARGINALDISTORTION ID-100 LENS28-200 f3.5-5.6 USM 1 ON 100 100 100 100 ID-111LENS14 mm F2.8L USM 1 ON 100 100 80 100 ID-015 LENS85 mm F1.2L II USM 1ON 100 100 0 0 ID-200 LENS-S18-55 mm F3.5-5.6 1 OFF 100 100 100 0 ID-003LENS28 mm F1.8 USM 1 ON 100 100 100 0 ID-035 LENS100-400 mm F45-5.6L ISUSM 0 OFF 0 0 0 0

As shown in Table 1, the table data relating to the lens unit stored inthe registration area is composed of lens ID, lens name, DL, ON/OFF,magnification, on axis, periphery, and distortion as line components,and the lens units as column components. Therefore, a variety of lensunit information can be registered in the table data by lens ID and lensname. Moreover, the number of lines in the table data is limited inadvance based on the capacity of the second memory 37 and the like.Therefore, in step S6, it is determined whether or not lens IDs and lensnames are registered up to the previously limited maximum number oflines.

In the table data, in S3 shown in FIG. 4 the data acquired from theattached lens unit is distinguished by lens ID and lens name so as notto be redundant and sequentially stored. The magnification, axis,periphery, and distortion comprise the lens unit correction information,and more specifically amount of correction by each of a plurality ofoptical characteristics (magnification chromatic aberration, axialchromatic aberration, decreased marginal illumination, and distortionaberration, in that order). ON/OFF is setting information for settingwhether or not to carry out correction of a sensed image usingcorrection information. DL is a flag that indicates whether or notdownloading and acquisition of correction information corresponding tothe lens ID and lens name acquired from the attached lens unit isfinished, shown as a numeric value of either 0 or 1 (O: acquisitionincomplete, 1: acquisition completed). It is to be noted that, in stepS9, initialized data (0, OFF, NULL value, etc.) is stored for the DL,ON/OFF, magnification, axial, marginal, and distortion for a lens ID andlens name newly registered in step S8.

In the example of Table 1, 6 types of lens units are registered in theimage sensing apparatus 2. However, with respect to the last registeredlens unit, the DL and the setting information and the correctioninformation have been initialized in step S9. In other words, althoughit can be seen from the lens name and lens ID that the lens unit isregistered as a lens unit, the DL that is the flag that shows thatcorrection information has been stored is 0, and 0 (or OFF or NULLvalue) is set for the setting information and for the correctioninformation. For all the other registered lens units, settinginformation and correction information have been stored and the DL flagis 1.

Thus, as described above, correction information for the attached lensunit is registered in the registration area of the second memory 37. Inaddition, by storing the DL flag as 0 in the registration area of thesecond memory 37, history information that includes identificationinformation acquired from the attached lens unit is stored. It is to benoted that it is not necessary that the history information and thecorrection information for the attached lens unit be stored in the sameregistration area, and alternatively, they may be stored in separatestorage devices or separate storage areas.

Next, with reference to FIG. 5, a description is given of the process ofregistering lens data stored in the external memory 39 in the imagesensing apparatus 2, which is a process that the CPU 36 carries out whenthe external memory 39 is connected to the image sensing apparatus 2.The flowchart shown in FIG. 5 illustrates steps in a process executed bythe CPU 36 when the external memory 39 is connected to the image sensingapparatus 2 at the time of turning off the image sensing apparatus 2. Itis to be noted that the process illustrated by the flowchart shown inFIG. 5 is such that, so long as the process is carried out when theexternal memory 39 is connected to the image sensing apparatus 2, theprocess may be executed not when turning off the image sensing apparatus2 but when turning on the image sensing apparatus 2. Moreover, althoughthe present embodiment illustrates a case in which the external memory39, which is a recording medium, is connected to the image sensingapparatus 2, it goes without saying that the process is the same also ina case in which an external device is connected.

In step S11, the CPU 36 determines whether or not, of the registeredlens units, there are those for which correction information has notbeen downloaded to the second memory 37, which it determines by checkingthe above-described DL flag. That is, in step S11, the CPU 36 determineswhether or not correction information for lens units with registeredlens IDs has been registered. If in step S11 all the DLs for theregistered lens units are 1 and the registered lens unit correctioninformation has all been downloaded (NO), the CPU 36 ends the process(step S12).

However, if in step S11 there is a lens unit with a DL of 0 andcorrection information has not been downloaded, the CPU 36 determineswhether or not lens data storing a variety of information by lens unitis contained in the external memory 39 (step S13). The lens data is filedata or the like storing a variety of information including correctioninformation by lens name and lens ID. For example, the lens data may beCSV (Comma Separated Value) format file data, with a variety ofinformation (lens name, lens ID, correction information) relating to asingle lens unit in one line separated by commas, with multiple piecesof lens unit correction information stored by identification informationextending over multiple lines. In other words, in step S13, the CPU 36determines whether or not at least a single piece of lens unitcorrection information is contained in the external memory 39.

If in step S13 it is determined that no lens data is contained in theexternal memory 39, the CPU 36 causes the display unit 41 to display forseveral seconds a warning message to the effect that no lens data iscontained in the external memory 39 (step S14). More specifically, sinceno lens data is contained in the external memory 39, the CPU 36 causesthe display unit 41 to display for several seconds a message such as“There are lens units registered for which correction information hasnot been downloaded.” This warning message display enables the user toascertain that lens units for which no correction information has beendownloaded are registered in the image sensing apparatus 2. Then, theCPU 36 ends the process (step S15).

Alternatively, if in step S13 it is determined that lens data iscontained in the external memory 39, the CPU 36 determines whether ornot correction information for the lens ID of the lens unit for whichcorrection information has not been downloaded is included in that lensdata (S16).

If in step S16 there is no correction information for the lens IDincluded in the lens data (NO), the CPU 36 causes the display unit 41 todisplay for several seconds a warning message to the effect thatcorrection information for the lens ID is not included in the lens data(step S17). More specifically, since no correction information for thelens ID is included in the lens data, the CPU 36 causes the display unit41 to display for several seconds a message such as “There is nocorrection information. Please update the file.” This warning messagedisplay enables the user to ascertain that correction information forthe lens unit that is registered in the image sensing apparatus 2 cannotbe registered with the lens data that is in the external memory 39, andthat it is necessary to update the lens data. Then, the CPU 36 ends theprocess (step S18).

On the other hand, if in step S16 correction information for the lens IDis included in the lens data, the CPU 36 stores that correctioninformation in the second memory 37 as correction information for thelens ID (step S19). More specifically, in step S19 correctioninformation is registered in the line of the lens ID in the table datadescribed above. It is to be noted that even if there is correctioninformation for the lens ID in the lens data in the external memory 39that has not yet been registered in the second memory 37, the CPU 36does not store that correction information in the second memory 37. Thisis because if correction information for a lens unit that has never beenattached to the image sensing apparatus 2 is stored in the second memory37 there is a strong possibility that space in the registration area ofthe second memory 37 will be needlessly decreased. Then, the CPU 36rewrites the DL flag for that lens ID to 1, to show that download iscomplete (step S20). Then, the CPU 36 causes the display unit 41 todisplay for several seconds a message such as “Lens unit correctioninformation storage complete.” (step S21), and ends the process (stepS22).

Next, with reference to FIG. 6, a description is given of a userinterface that receives from the user settings for each lens unit forwhich correction information is downloaded, and setting whether or notto carry out correction using that correction information. FIG. 6 showsan example of a setting screen G1 displayed on the display unit 41.

The setting screen G1 is a screen that is displayed on the display unit41 by the CPU 36 sequentially executing user interface program datastored in the second memory 37. When the setting screen G1 is displayedon the display unit 41, the CPU 36 through the switch 40 receivesoperating instructions from the user. On the setting screen G1, lensnames registered in the second memory 37 can be selected using theselection button G11, with setting information and correctioninformation relating to the selected lens name being read out from thesecond memory 37 and displayed. A setting button G12 queries the userand sets the ON/OFF as to whether or not to carry out correction of asensed image using the correction information. A setting button G13queries the user as to the amount of correction relating tomagnification chromatic aberration correction in the correctioninformation and receives correction instructions from the user. Asetting button G14 queries the user as to the amount of correctionrelating to axial chromatic aberration correction in the correctioninformation and receives correction instructions from the user. Asetting button G15 queries the user as to the amount of correctionrelating to decreased marginal illumination correction in the correctioninformation and receives correction instructions from the user. Asetting button G16 queries the user as to the amount of correctionrelating to distortion aberration correction in the correctioninformation and receives correction instructions from the user.

Using the above-described setting screen G1, at the image sensingapparatus 2 various settings are implemented with respect to thecorrection information for the lens unit selected with the selectionbutton G11 from among the lens units registered in the second memory 37,using the setting buttons G12 through G16. In addition, the settingresults obtained with the setting screen G1 are reflected as settinginformation and correction information for the lens units registered inthe second memory 37.

Thus, as described above, at the image sensing apparatus 2, a lens unitfor which correction information has been downloaded can be selectedusing the user interface that displays the setting screen G1 on thedisplay unit 41 and receives user operating instructions from the switch40. Moreover, for the lens unit selected using the user interface, it ispossible to select an item that turns all the correction functionsON/OFF, that is, it is possible to select whether or not to carry outcorrection using correction information. In addition, in a case in whichthe correction function is switched ON, the amount of correction ofindividual correction items, which are magnification chromaticaberration correction, axial chromatic aberration correction, decreasedmarginal illumination correction, distortion aberration correction, andso on can be individually adjusted to appropriate amounts. It is to benoted that, in a case in which the correction function is switched OFF,reception of operation of the setting buttons G13-G16 may be disabled.When carrying out image sensing using a lens unit for which correctioninformation is set with the user interface shown as an example in FIG.6, the user can correct the sensed image by a desired amount ofcorrection, and store the corrected image in the external memory 39.

(Second Embodiment)

In the first embodiment, the image sensing apparatus 2 automaticallyreads out correction information of a lens unit from the external memory39 and registers the read-out correction information. A secondembodiment is described using as an example a method of registering froman external device such as a PC or the like connected to the imagesensing apparatus 2, as another method of registering lens unitcorrection information in the image sensing apparatus 2. It is to benoted that, in the following description, elements of the image sensingapparatus 2 that are the same as those of the first embodiment are giventhe same reference numerals and redundant description thereof isomitted.

FIG. 7 is a schematic diagram illustrating a system configurationaccording to the second embodiment. As shown in FIG. 7, in this secondembodiment the image sensing apparatus 2 is connected to a registrationapparatus 50 through the above-described I/F unit 38. The registrationapparatus 50 is a PC or other such information device, and has a CPU,ROM, RAM, operating devices such as a keyboard and a mouse, and acommunications interface for exchanging data with other devices (none ofwhich is shown). By the CPU securing operating areas in the RAM andsequentially executing program data stored in the ROM, the registrationapparatus 50 performs various types of data processing in response toinstructions from a user input through the operating devices. A displaydevice 51 such as an LCD is connected to the registration apparatus 50through a communications interface, enabling display of operatingscreens, data processing results, and the like on the display device 51.

The registration apparatus 50 communicates with the image sensingapparatus 2 through the communications interface and can obtain datastored in the image sensing apparatus 2. More specifically, theregistration apparatus 50 exchanges data with the image sensingapparatus 2 through a communications interface such as a USB or thelike, and can obtain data corresponding to Table 1 stored in the secondmemory 37. In addition, the recording apparatus 50 is connectable to theinternet 60 through a communication interface. Accordingly, byspecifying an IP address or the like at the registration apparatus 50and specifying a data server 61 connected to the internet 60, it ispossible to download data stored on the data server 61. Alternatively,the registration apparatus 50 may be connectable to a storage device orother recording medium through a communications interface, and downloaddata stored on the recording medium. It is to be noted that, in thesecond embodiment, the registration apparatus 50 downloads data storedon the data server 61.

The data server 61 is for example a storage device containing lens datafor all lens units, providing lens data to devices from which there is arequest (clients) over the internet 60. Therefore, whereas in the firstembodiment lens data containing lens unit correction information wasdownloaded from an external memory, in this second embodiment lens datacan be downloaded from the data server 61.

Next, with reference to FIG. 8, a description is given of the process oftransmitting correction information to be registered in the imagesensing apparatus 2 from the registration apparatus 50 in order toregister correction information in the image sensing apparatus 2, whichis a process that the CPU of the registration apparatus 50 carries outsequentially. It is to be noted that this process is carried out whenthe CPU of the registration apparatus 50 detects connection with theimage sensing apparatus 2, and is commenced, for example, by specifyingexecution of a program for diagnosing the image sensing apparatus 2 whenthe image sensing apparatus 2 is connected.

As shown in FIG. 8, when processing is commenced, the CPU of theregistration apparatus 50 acquires data corresponding to Table 1 storedin the image sensing apparatus 2 and determines whether or not, of thelens units registered in the image sensing apparatus 2, there are thosefor which correction information has not been downloaded (step S31). Ifin step S31 correction information has been downloaded for all theregistered lens units (NO), the CPU displays a message such as “Nocorrection information to be added.” on the display device 51 and endsthe diagnostic program (step S32).

If in S31 there are lens units registered for which correctioninformation has not been downloaded, the CPU determines whether or notthe registration apparatus 50 is connected to the internet 60 (stepS33). In step S33, if the registration apparatus 50 is not connected tothe internet 60, the CPU displays a warning message such as “Pleaseconnect to the internet to download correction information.” on thedisplay device 51 (step S34). Then, the CPU ends the diagnostic program(step S35).

If in step S33 the registration apparatus 50 is connected to theinternet 60, the CPU connects the registration apparatus 50 to the dataserver 61 that is a predetermined connection address containingcorrection information, using an IP address or the like preset in thediagnostic program (step S36). Then, the CPU downloads lens data for thelens ID of the lens unit, for which no correction information has beendownloaded, from the data server 61 to the RAM or the like (step S37).

It is to be noted that, in step S37, the CPU may carry out the sameprocesses as those of steps S13-S18 in the first embodiment based on thelens data downloaded to the RAM. In this case, in the event that thedownloaded lens data does not satisfy the determinations of step S13 orS16, the same warning messages as in steps S14 and S17 are displayed onthe display device 51.

Then, the CPU causes the display unit 51 to display an indication to theeffect that the correction information included in the lens datadownloaded from the data server 61 is being registered in the imagesensing apparatus 2 (step S38). Then, the CPU transmits the correctioninformation included in the lens data downloaded form the data server 61to the image sensing apparatus 2 as correction information to beregistered, and registers it in the second memory (step S39). Then, theCPU displays a message such as “Correction information updatecompleted.” on the display unit 51 and ends the diagnostic program (stepS40).

It is to be noted that when the CPU of the registration apparatus 50transmits correction information to the image sensing apparatus 2 instep S39, a user interface like that shown in FIG. 6 may be provided bysequentially executing the above-described user interface program data.More specifically, various settings relating to the correctioninformation to be transmitted to the image sensing apparatus 2 may becarried out by displaying the above-described setting screen G1 on thedisplay unit 51 and receiving user instructions from the operatingdevices. In this case, as with the user interface in the image sensingapparatus 2, the user can register correction information that correctsthe sensed image by a desired correction amount in the image sensingapparatus 2.

Although in the second embodiment the registration apparatus 50 isconfigured to download lens data from the data server 61, the source ofthe lens data is not limited to the data server 61. For example, theregistration apparatus 50 may be configured to read out lens data from astorage device built into the apparatus or from an external memoryconnected through an interface.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed in exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2008-275923, filed on Oct. 27, 2008, which is hereby incorporated byreference herein in its entirety.

1. An image sensing apparatus including a correction unit that correctsa sensed image based on correction information for an attached lens unitregistered in advance in a correction information storage unit, in whichthe lens unit is detachable, the image sensing apparatus comprising: anacquisition unit that acquires identification information for anattached lens unit from the attached lens unit and, if the acquiredidentification information is different from identification informationwhich has been acquired previously, registers in the correctioninformation storage unit the acquired identification information and aflag indicating that correction information for the acquiredidentification information is not registered in the correctioninformation storage unit; a connection unit that connects to an externaldevice storing multiple pieces of correction information for differentlens units by identification information; and a control unit that, in acase where the external device is connected to the image sensingapparatus and the flag exists, reads out correction information for theidentification information corresponding to the flag from the externaldevice, registers the read-out correction information in the correctioninformation storage unit, and changes the flag to a flag indicating thatthe correction information has been registered in the correctioninformation storage unit.
 2. The image sensing apparatus according toclaim 1, further comprising a display unit, wherein the control unitdetermines whether or not at least one piece of the correctioninformation is stored in the external device connected by the connectionunit, and in a case in which there is no such correction informationstored, displays a warning message on the display unit indicating thatno such correction information is stored.
 3. The image sensing apparatusaccording to claim 1, further comprising a display unit, wherein thecontrol unit determines whether or not correction information for theflag indicating that the correction information is not stored is storedin the external device connected by the connection unit, and in a casein which there is no such correction information stored, displays awarning message on the display unit indicating that no such correctioninformation is stored.
 4. The image sensing apparatus according to claim1, further comprising a user interface that receives user instructions,wherein a correction amount for correcting a plurality of opticalcharacteristics of the lens unit is set in the correction information,wherein the control unit changes the correction amount set in thecorrection information registered in the correction information storageunit based on a user instruction received from the user interface. 5.The image sensing apparatus according to claim 1, wherein the externaldevice is a recording medium detachably attachable to the connectionunit or a data server communicably connectible to the connection unit.6. A control method for an image sensing apparatus including acorrection unit that corrects a sensed image based on correctioninformation for an attached lens unit registered in advance in acorrection information storage unit, in which the lens unit isdetachable, and a connection unit that connects to an external devicestoring multiple pieces of correction information for different lensunits by identification information, the control method comprising: anacquisition step of acquiring identification information for an attachedlens unit from the attached lens unit and, if the acquiredidentification information is different from identification informationwhich has been acquired previously, registering in the correctioninformation storage unit the acquired identification information and aflag indicating that correction information for the acquiredidentification information is not registered in the correctioninformation storage unit; and a control step of, in a case where theexternal device is connected to the image sensing apparatus and the flagexists, reading out correction information for the identificationinformation corresponding to the flag from the external device,registering the read-out correction information in the correctioninformation storage unit, and changing the flag to a flag indicatingthat the correction information has been registered in the correctioninformation storage unit.
 7. A non-transitory computer-readable mediumincluding a program stored thereon, the program when executed by aninformation processing apparatus causing the information processingapparatus to perform the control method as set forth in claim 6.